This small city where almost everyone lives in the same building can only be reached via North America's longest tunnel.

Running under an entire mountain, the longest highway tunnel in North America is kept fresh using portal fans and jet fans.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

Wedding chapel's mysterious spiral staircase said to be miraculously constructed.

The official atomic museum of the United States explores the explosive and productive history of a much maligned energy source.

Only known mainland rookery of the threatened Stellar sea lion.

A collection of colorful dinosaurs hidden in an actual rainforest.

A massive sea stack famous for its appearance in The Goonies.

No one knows how this Pacific Northwest spruce tree came to have so many trunks.

100-year-old shipwreck you can walk up to at low tide.

A tourist attraction founded around a slumping cabin.

A walk through the historic city center, under the streets of Seattle.

A museum dedicated to the history and exploration of both popular music and science fiction.

Home of Howard Hughes' Spruce Goose.

The largest wooden building in the world now houses a fascinating collection of aircraft.

A Roman-style column in Oregon hides a spiral staircase inside.

The longest continuous lava tube in the continental U.S. offers 2.5 miles of dark explorations for the adventurous.

The seamy, underground secrets of Portland's criminal past.

This public art piece proves that in Portland even reporting the weather is a thing of whimsy.

The magic's in the hole!

Portlandia is the second-largest copper repoussé statue in the United States.

Featuring a casually threatening atmosphere along with dessert and coffee to die for.

A beautiful 62-acre Catholic shrine and botanical garden.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.